Re: libata badness

On Monday October 4, wknop@andrew.cmu.edu wrote:

CPU:    0
EIP:    0060:[<229e4d8c>]    Not tainted
EFLAGS: 00010206   (2.6.8-1.521)
EIP is at handle_stripe+0x29a/0x1407 [raid5]
eax: 00000001   ebx: 00000000   ecx: 00915cb8   edx: 21f7e1c0
esi: 1ccbd118   edi: 21f7e1c0   ebp: 01000000   esp: 1d300f28
ds: 007b   es: 007b   ss: 0068
Process md0_raid5 (pid: 2626, threadinfo=1d300000 task=1d317970)
Stack: 2283eb57 20db8000 21f7e1c0 21c30288 1ccbd204 20db8000 00000001 
1ccbd158
        00000002 00000000 00000000 00000001 00000000 00000000 00000001 
00000000
        00000001 00000001 00000000 00000003 1ccbd0ac 21f7e1c0 1ccbd0ac 
21f76c00
Call Trace:
  [<2283eb57>] ata_scsi_queuecmd+0xbe/0xc7 [libata]
  [<229e6b1c>] raid5d+0x1ce/0x2f8 [raid5]
  [<0228f5d2>] md_thread+0x227/0x256
  [<0211be05>] autoremove_wake_function+0x0/0x2d
  [<0211be05>] autoremove_wake_function+0x0/0x2d
  [<0228f3ab>] md_thread+0x0/0x256
  [<021041d9>] kernel_thread_helper+0x5/0xb
Code: 8b 55 04 83 c1 08 8b 45 00 83 d3 00 39 da 72 0e 0f 87 e0 01

This code starts:

   0:   8b 55 04                  mov    0x4(%ebp),%edx
   3:   83 c1 08                  add    $0x8,%ecx

and as %ebp is 01000000, this oopses.  
It looks very much like a single-bit memory error (as has already been
suggested as a possibility).

NeilBrown